Structure and magnetic properties of Sr2NiAO6 (A = W, Te)

Abstract Crystal structures and magnetic properties of the B-site ordered perovskites Sr 2 NiWO 6 and Sr 2 NiTeO 6 were investigated. Powder X-ray diffraction analysis revealed that Sr 2 NiWO 6 and Sr 2 NiTeO 6 have the tetragonal structure of I 4/ m (No. 87) and the monoclinic structure of C 2/ m (No. 12-2), respectively. Magnetic measurement of Sr 2 NiWO 6 and Sr 2 NiTeO 6 revealed that antiferromagnetic transition appears at 54 and 35 K, respectively. Heat capacity measurement gave a different transition temperature of 28 K for Sr 2 NiTeO 6 . Analysis of the entropy of the three-dimensional antiferromagnetic transition revealed that local ordering of spins begins at higher temperatures of observed T N , especially in Sr 2 NiTeO 6 .